We are currently experiencing a dispute with our contractor.

Its a tough choice and, though I'm not permitted to directly advise you due to the nature of this service, you would definitely have the option to complete the project with another party and counter sue for the difference.

You would normally let him sue at this point because you're in the position of still having the funds. If his invoice is the "final invoice" as you've indicated and there is still substantial work to be completed, then you would make the case that there was much more work than the $300 clean-up to finish. This would likely be born out in the quotes you receive.

If you do finish the work with a third-person there is, of course, a risk that a judge will side with the Plaintiff (the builder) and require to to pay all or part of the amount owed but that is, unfortunately, the risk associated with any litigation matter. (And consequently, he also runs the risk of not recovering anything and of having to pay you the difference between the amount owed and what it would cost to have a third party finish the work).

What I would do, is get the quotes, see where they are based on the work needed to be completed and advise him that you're requesting he come and finish the work before payment is made and that the amount to be completed is greater than the hold-back (if that is the case). Then follow-up in writing and give him a reasonable amount of time to show up and complete the job (5 days perhaps). If he threatens again simply state (and follow-up with a letter) that he's left you no option but to mitigate your losses and have another party come into finish the job and that you will be countersuing for the additional costs in so doing. This position may get him to at least start negotiating (and do give yourself some time before you actually have someone show up to do the work).

Also, be sure to journal every interaction with him going forward.

Regards XXXXX XXXXX wishes.